A shared cell procurement and analysis laboratory is proposed for the program project. This laboratory will serve an essential function in all four subprojects of the program project. This core will coordinate and perform flow cytometry and immunohistochemistry for purification and/or analysis of hematopoietic cells for the proposed studies. The present flow cytometry research laboratory which will be part of the proposed core unit is fully equipped with state of the art instrumentation for the performance of sophisticated flow cytometry procedures required by the proposed studies. The flow cytometry laboratory is currently located in a separate 400 square feet room on the fifth floor of the Medical Research and Library Building and will be relocated into a larger laboratory space on the first floor of the new Research Building projected to be completed in 1996. The laboratory activity is currently supported by two full time employees both of whom are well qualified operators who have received extensive training in flow cytometry. An additional employee is expected to join the core unit with the sole responsibility of procuring and preparing tissues and sorted cell populations for researchers involved in the proposed program project. The shared cell procurement and analysis laboratory will provide for participants in the program project an economical use of equipment and space as well as necessary cell populations required for the conduct of the research. The immunohistology laboratory which will be part of the proposed core unit is fully equipped to immunocharacterize animal and human hematopoietic and non-hematopoietic cells using antibodies specific for cell derivation, cell activation or oncogene products. In addition the laboratory can perform cytokinetic analysis of the specimens using the monoclonal antibodies and can assess cell apoptosis by a peroxidase DNA and labeling technique. The laboratory is located in a 210 square feet facility within the Division of Hematopathology of the Department of Pathology at the fourth floor of the I.U. Hospital. The laboratory is currently staffed by two full time techologists who have extensive experience in both research and routine immunohistology.